1. Field of the Invention
The present invention relates to high frequency heating apparatuses, particularly to high frequency heating apparatuses of various types such as a microwave oven.
2. Description of the Background Art
In conventional cases, a microwave oven may be installed above a cooking counter such as a kitchen stove counter from the standpoint of effectively utilizing the space above the cooking counter.
When cooking is carried out at the cooking counter, the heat therefrom rises to adversely affect the microwave oven. An approach could be taken to install a ventilation fan at the microwave oven per se to drive the fan to discharge the heat.
In a conventional microwave oven, the start and end of a ventilation operation was effected through the key operation of the user.
In the conventional case, the user had to operate the end specification key in order to terminate the ventilation operation. This may be a bother to the user. In the case the user forgets to operate the end key, the ventilation operation will be continued to result in wasting power consumption.
In order to eliminate the key operation by the user to terminate the ventilation operation, the applicant of the present invention considered that the conventional problem can be solved by utilizing a timer, for example, to automatically terminate the ventilation operation at an elapse of a predetermined time from the start of the ventilation operation. In this case, the key operation is bothersome since the key operation to initiate a ventilation operation and the key operation to specify the operation period of time of the ventilation operation had to be carried out. If the period of time of the ventilation operation is to be set based on the unit of one minute per one operation, for example, the number of key operations required will increase as a longer operation period of time is to be set such as 10 minutes, 20 minutes, and the like. The operation load on the user is rather heavy in such a conventional high frequency heating apparatuses. There was a problem that the usability thereof is poor and bothersome.